build: remove devShell

I don't use it anyways and apparently this is deprecated now.
I might add it back when I switch to flake-parts, but that's in the future anwyays.

flake.nix

@@ -115,10 +115,5 @@
           };
         };
       };
-
-      devShell = nixpkgs.legacyPackages.${system}.mkShell {
-        inherit (self.checks.${system}.pre-commit-check) shellHook;
-        buildInputs = self.checks.${system}.pre-commit-check.enabledPackages;
-      };
     });
 }